Surgical knife



July 29, 1958 w. A. sHAl-'ER 2,845,072

SURGICAL KNIFE Filed June 21, 1955 imail, Amplif/ar W//idm 'A Shafer 1N VEN TOR.

wrydvgnv United States Patent O SURGICAL KNIFE William A. Shafer, Erie, Pa.

Application June 21, 1955, Serial No. 516,967

2 Claims. (Cl. 128-303.14)

This invention relates generally to surgical knives, and more particularly to instruments having reciprocating blades.

The primary object of the present invention resides in the provision of a surgical knife having means for reciprocating the blade at a controlled frequency to thereby enable a physician to undertake delicate surgical procedures by minimizing the possibility of tearing.

A further object of the invention resides in the provision of a surgical knife which minimizes the pain of cuttingrdue to the fact that the blade is reciprocating at high speeds to which the patients body is not immediately sensitive.

A further object of the invention resides in the provision of a surgical knife having a reciprocating blade the frequency of which may be controlled so that the blade is reciprocated at a desired frequency for various procedures.

Still further objects and features of this invention reside in the provision of a surgical knife that is simple in construction, highly efficient in operation, relatively light in weight and easily carried, and which is highly eicient in use while being relatively inexpensive to produce, thereby permitting wide distribution and utilization.

These, together with the various ancillary objects and features of the invention which will become apparent as the following description proceeds, are attained by this surgical knife, a preferred embodiment of which has been illustrated in the accompanying drawings, by way of example only, wherein:

Figure l is a perspective view of a surgical knife according to my invention;

Figure 2 is alongitudinal sectional view as taken along the plane of line 2-2 in Figure l and showing the surgical knife in an enlarged scale;

Figure 3 is a horizontal sectional view as taken along the plane of line 3 3 in Figure 2;

Figure 4 is a schematic diagram of the electrical components of the invention.

With continuing reference to the accompanying drawings wherein like reference numerals refer to similar parts throughout the various views, and with initial attention directed to the embodiment of the invention of Figure l, reference numeral 20 is used to generally designate the surgical knife comprising the present invention. This surgical knife includes a shaft 22 receivable within a casing 24 which has threadedly secured thereto, as at 26, the neck portion 28 of a housing 30 which is formed 1n two parts that are threadedly secured to each other, as

v2,845,072 Patented July 29, 1958 at 32, the upper portion of the housing 34 having a threaded neck portion 36 to which an upper portion 38 of the casing is threadedly secured.

Mounted within the casing 24 is a bearing 40 of nylon or other suitable material through which the shaft 2.2 extends, the bearing 40 forming a suitable guide for the reciprocating shaft 22. Detachably secured by means of a conventional detachable blade connection is a surgical blade 42 of conventional construction.

Within the housing 30, there is located a piezoelectric crystal 44 having a plate 46 at its lower end which has a threaded tubular socket 48 to which the upper threaded end of the shaft 22 is attached. This plate 46 is grounded to the frame, and an upper plate 50 of the crystal 44 has a conductor 52 connected thereto which extends through the guide portion 54 of the casing 38. A second lead S6 is grounded to the casing, as at 58. A variable audio oscillator 60 is connected to the crystal 44 through the audio amplier 62 and by varying the frequency of the output of the oscillator 60 and therefore the amplifier 62, the crystal 44 will cause the plate 46 to vibrate at a predetermined and controlled rate. The housing 30 is formed in sections so as to permit the ready replacement of the crystal 44, as desired.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

l. A surgical knife comprising a casing, a shaft mounted in said casing for reciprocating movement and having an end portion extending outwardly of said casing, a blade detachably secured to said shaft, drive means in said casing for reciprocating said shaft, and control means for controlling the frequency of the reciprocatory movement imparted to said shaft by said drive means, said drive means including a piezoelectric crystal connected to said shaft, said control means comprising a variable audio oscillator coupled through an amplifier to said piezoelectric crystal.

2. A surgical knife comprising a casing, a shaft mounted in said casing for reciprocating movement and having an end portion extending outwardly of said casing, a blade detachably secured to said shaft, drive means in said casing for reciprocating said shaft, and control means for controlling the frequency of the reciprocatory movement imparted to said shaft by said drive means, said drive means including a piezoelectric crystal connected to said shaft, said control means comprising a variable audio oscillator coupled through an amplifier to said piezoelectric crystal, said casing having a housing for said piezoelectric crystal detachably secured thereto.

References Cited in the tile of this patent UNITED STATES PATENTS 1,675,805 Holcomb July 3, 1928 1,966,446 Hayes July 17, 1934 2,714,890 Vang Aug. 9, 1955 2,730,103 Mackta Ian. 10, 1956 

